Timothy, I can relate to the feeling. As Megalodon and Tpmetal have suggested, swinging your detector may get easier over time. Are you sure though, that this is the right pursuit for you? I say that gently and with good intentions, because many people have gone through the ups and downs of this hobby and found it not to be right for them. The stooping, kneeling, crawling, or whatever contortions bring you closer to your target get tougher, not easier, if you set your sights too high initially. I speak from experience.
In 2006 I was diagnosed with heavy metal poisoning - specifically arsenic. (No, my wife of 50 years was not involved in any way. I know because she told me so.) That itself is another story but the nerve damage was done and my legs simply don't work the way they used to. I reasoned that metal detecting would help me therapeutically so I did my research and jumped in. Boy, was I in for a surprise! My weight, largely through inactivity, had soared to nearly 300 pounds from 210. My balance was badly affected. But I was determined to learn what I could do with my new AT Pro. So after reading the manual, back yard practice, and many visits to you-know-what-tube I felt ready.
What a shocker! I recall falling to my knees to dig for my first "find."It hurt like hell and I couldn't get up without the help of my two collapsible walking sticks. Sitting on a small footstool didn't help much either. So I resigned myself to the undignified positions that I would have to assume while rising and kneeling to dig and to examine my finds. I crawled, rolled, walked on my knees, and generally ignored what others may have been thinking as they watched me. (Besides, when asked if I was okay I had my arsenic story ready to go.It made for some interesting conversation.) Gradually I figured out best ways to proceed. The biggest relief came when I was able to accept my limitations and slow down. After all, what was lost was most likely going to be there tomorrow waiting for my return.
Today I weigh 215 pounds, which is 7 pounds more than I weighed when I was 25 and playing hockey two nights a week. Metal detecting actually had very little to do with my weight loss in the physical sense, but it sure helped by giving me something to replace my old field activities with. I learned that the interest in hunting as opposed to finding was my personal driving force. Today at 70 I hurt plenty but I've learned to work within my limitations, take my time, and to enjoy the search. Note that I don't bother to record my finds, which to this point have been quite unremarkable. It's the hunt that has always appealed to me.
Timothy, it is entirely possible that this is not the right pastime for you. If that is the case, don't feel too badly about moving on. But as others have urged, consider adjusting your thinking as well as easing into the physical effort before you bail. By all means work within your budget to try something else. Or, think about expanding your efforts to include more than one activity. Rockhounding and fossil collecting are my complimentary activities, and my "Bucket List" now includes gold prospecting. (I don't have illusions about striking it rich. I just want to read, learn, and discuss, to ultimately see "colors" in my pan.) All of this can be done at the same time.
Finally, in my opinion you have taken the right steps in joining this forum and in freely discussing your situation. Don 't be too hard on others who may not understand the hobby or your interest in it. I've seen many solo detectorists - in fact I am one myself. Just consider your overall situation and you will make the right choice.
